Config: Rx  Descram (Descrambler); Config: Rx  Eq (Equalizer) - Comtech EF Data CDM-625A Installation And Operation Manual

CDM-625A Advanced Satellite Modem
Front Panel Operation
6.2.1.4.7 CONFIG: Rx  Descram (Descrambler)
Rx Descrambler = IESS (Normal,IESS,Off)
Use the arrow keys to select Normal, IESS, or Off, and then press ENTER.
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The modem automatically selects the actual scrambler used for Normal, depending on the exact
operating mode:
•
If framing = IBS/D&I, the IESS-309 scrambler is used.
•
If Reed-Solomon is on but IBS/D&I is off, its frame synchronous scrambler is used per
IESS-310, App. H. An exception to this is legacy EF Data Reed-Solomon, which uses a
proprietary modified V.35 scrambler instead.
•
If framing = EDMAC/2/3 and Reed-Solomon is off, its frame synchronous scrambler is
used.
•
If configured for TPC (Turbo) encoding and all of the above settings are off, the TPC
frame scrambler is used except for 8-QAM. For CDM-570 compatibility, TPC with 8-QAM
uses the V.35 scrambler.
•
ITU V.35 scrambler (Intelsat variant) is the default scrambler when all of the above
settings are off.
When selecting IESS, the default ITU V.35 scrambler specified in IESS-315 takes priority over all
"normal" scramblers and is used instead. Therefore, for many operating modes, the two
scrambler choices are redundant.
When using TPC and Carrier-in-Carrier simultaneously, the IESS-315 (V.35) scrambler is the only
permitted choice.
6.2.1.4.8 CONFIG: Rx  Eq (Equalizer)
Rx Equalizer:
Use the arrow keys to select Enable or Disable, and then press ENTER. The integrated 5-tap
▲▼
adaptive equalizer can compensate for:
•
Amplitude slope and variation over the symbol bandwidth.
•
Non-linear group delay variation over the symbol bandwidth.
IESS-315 V.35 Scrambler
Disabled (Enable,Disable)
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Revision 0
MN-CDM625A
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